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Effects of walnut consumption on cognitive performance in young adults

  • Peter Pribis (a1), Rudolph N. Bailey (a2), Andrew A. Russell (a2), Marcia A. Kilsby (a3), Magaly Hernandez (a1), Winston J. Craig (a1), Tevni Grajales (a2), David J. Shavlik (a4) and Joan Sabatè (a5)...

Walnuts contain a number of potentially neuroprotective compounds like vitamin E, folate, melatonin, several antioxidative polyphenols and significant amounts of n-3 α-linolenic fatty acid. The present study sought to determine the effect of walnuts on verbal and non-verbal reasoning, memory and mood. A total of sixty-four college students were randomly assigned to two treatment sequences in a crossover fashion: walnuts–placebo or placebo–walnuts. Baseline data were collected for non-verbal reasoning, verbal reasoning, memory and mood states. Data were collected again after 8 weeks of intervention. After 6 weeks of washout, the intervention groups followed the diets in reverse order. Data were collected once more at the end of the 8-week intervention period. No significant increases were detected for mood, non-verbal reasoning or memory on the walnut-supplemented diet. However, inferential verbal reasoning increased significantly by 11·2 %, indicating a medium effect size (P = 0·009; d = 0·567). In young, healthy, normal adults, walnuts do not appear to improve memory, mood or non-verbal reasoning abilities. However, walnuts may have the ability to increase inferential reasoning.

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*Corresponding author: Dr P. Pribis, fax +1 269 471 3485, email
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1Wainwright PE (2000) Nutrition and behavior: the role of n-3 fatty acids in cognitive functions. Br J Nutr 83, 337339.
2Kang JH, Asherio A & Grodstein F (2005) Fruit and vegetable consumption and cognitive decline in aging women. Ann Neurol 57, 713720.
3Morris MC, Evans DA, Tangney CC, et al. (2006) Associations of vegetable and fruit consumption with age-related cognitive change. Neurology 67, 13701376.
4Willis LM, Shukitt-Hale B, Cheng V, et al. (2009) Dose-depended effect of walnuts on motor and cognitive function in aged rats. Br J Nutr 101, 11401144.
5Morley JE & Banks WA (2010) Lipids and cognition. J Alzheimers Dis 20, 737747.
6van Gelder BM, Tijhuis M, Kalmijn S, et al. (2007) Fish consumption, n-3 fatty acids, and subsequent 5-y cognitive decline in elderly men: the Zutphen Study. Am J Clin Nutr 85, 11421147.
7Grandjean AC & Grandjean NR (2007) Dehydration and cognitive performance. J Am Coll Nutr 26, 549S554S.
8Morley JE (2010) Nutrition and the brain. Clin Geriatr Med 26, 8998.
9Crews C, Hough P, Godward J, et al. (2005) Study of main constituents of some authentic walnut oils. J Agric Food Chem 53, 48534860.
10Fukuda T, Ito H & Yoshida T (2003) Antioxidative polyphenols from walnuts (Juglans regia L.). Phytochemistry 63, 795801.
11Reiter RJ, Manchester LC & Tan DX (2005) Melatonin in walnuts: influence on levels of melatonin and total antioxidant capacity of blood. Nutrition 21, 920924.
12Halvorsen BL, Carlsen MH, Phillips KM, et al. (2006) Content of redox-active compounds (ie, antioxidants) in foods consumed in the United States. Am J Clin Nutr 84, 95135.
13Heinrichs SC (2010) Dietary ω-3 fatty acid supplementation for optimizing neuronal structure and function. Mol Nutr Food Res 54, 447456.
14Innis SM (2007) Dietary (n-3) fatty acids and brain development. J Nutr 137, 855859.
15Su K-P (2009) Biological mechanism of antidepressant effect of omega-3 fatty acids: how does fish oil act as a “Mind-Body interface”? Neurosignals 17, 144152.
16Nooyens ACJ, Bueno-de-Mesquita HB, van Boxtel MPJ, et al. (2011) Fruit and vegetable intake and cognitive decline in middle-aged men and women: the Doetinchem Cohort Study. Br J Nutr 106, 752761.
17Ritter-Gooder PK, Lewis NM, Heidal KB, et al. (2006) Validity and reliability of a quantitative food frequency questionnaire measuring n-3 fatty acid intake in cardiac patients in the Midwest: a validation pilot study. J Am Diet Assoc 106, 12511255.
18Evans AN & Rooney BJ (2011) Methods in Psychological Research, 2nd ed.Thousand Oaks, CA: SAGE Publications, Inc.
19Saghaei M (2004) Random allocation software for parallel group randomized trials. BMC Med Res Methodol 4, 26.
20Zock PL, Mensik RP, Harryvan J, et al. (1997) Fatty acids in serum cholesteryl esters as quantitative biomarkers of dietary intake in humans. Am J Epidemiol 145, 11141122.
21Lepage G & Roy CC (1986) Direct transesterification of all classes of lipids in a one-step-reaction. J Lipid Res 27, 114120.
22Raven J, Raven JC & Court JH (1998) Manual for Raven's Advanced Progressive Matrices, 1998 ed.San Antonio, TX: Harcourt Assessment, Inc.
23Raven J (2000) The Raven's progressive matrices: change and stability over culture and time. Cognitive Psychol 41, 148.
24El Hassan K & Madhum G (2007) Validating the Watson Glaser Critical Thinking Appraisal. High Educ 54, 361383.
25Watson G & Glaser EM (1980) Watson-Glaser Critical Thinking Appraisal Manual. San Antonio, TX: The Psychological Corporation – Harcourt Brace & Co.
26Wechsler D (2002) Wechsler Adult Intelligence Scale III – Third Edition. Technical Manual. San Antonio, TX: The Psychological Corporation – Harcourt Assessment Co.
27McNair DM & Heuchert JWP (2005) Profiles of Mood States – Technical Update. Toronto, ON: Multi-Health Systems, Inc.
28Nyenhuis DL, Yamamoto C, Luchetta T, et al. (1999) Adult and geriatric normative data and validation of the profile of mood states. J Clin Psychol 55, 7986.
29Cohen J (1998) Statistical Power for the Behavioral Sciences, 2nd ed.Hillsdale, NJ: Lawrence Erlbaum.
30Warner RM (2008) Applied Statistics. Thousand Oaks, CA: Sage Publications, Inc.
31Fontani G, Corradeshi F, Felici A, et al. (2005) Cognitive and physiological effects of omega-3 polyunsaturated fatty acids supplementation in healthy subjects. Eur J Clin Invest 35, 691699.
32Haag M (2003) Essential fatty acids and the brain. Can J Psychiatry 48, 195203.
33Edwards R, Peet M, Shay J, et al. (1998) Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord 48, 149155.
34Maes M, Christophe A, Delanghe J, et al. (1999) Lowered omega-3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients. Psychiatry Res 85, 275319.
35Peet M, Murphy B, Shay J, et al. (1998) Depletion of omega-3 fatty acid levels in red blood cell membranes of depressive patients. Biol Psychiatry 43, 315319.
36Appleton KM, Rogers PJ & Ness AR (2010) Updated systematic review and meta-analysis of effects of n-3 long-chain polyunsaturated fatty acids on depressed mood. Am J Clin Nutr 91, 757770.
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British Journal of Nutrition
  • ISSN: 0007-1145
  • EISSN: 1475-2662
  • URL: /core/journals/british-journal-of-nutrition
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